Abstract : This document presents the results and conclusions of archeological investigations on 57 prehistoric sites at Fort Hood in Bell and Coryell counties, Central Texas. The objective of the investigations was to test each site for eligibility for inclusion to the National Register of Historic Places (NRHP), as is required in the current Historic Preservation Plan for Fort Hood. Site research potential was assessed with respect to research questions and data needs outlined in the existing prehistoric research design for Fort Hood. Sites with significant research potential, as demonstrated by diverse abundant data sets, were assessed as eligible for inclusion to the NRHP. The 57 prehistoric sites were tested using manually excavated test pits and mechanically excavated trenches. At two rockshelters, powered rock saws were used to recover samples of indurated tufa. The test pits ranged in depth from 20 cm to 620 cm below the modern surface. Testing documented a total of 116 features including 47 hearths, 26 burned rock concentrations, 25 burned rock middens, 8 burned rock mounds, 4 burned rock pavements, two lithic caches, and one each of mussel shell concentration, carbonized post, ash lens, and burial pit. Fieldwork recovered a total of 78,893 artifacts and samples, including 66,543 prehistoric and 75 historic artifacts. The most frequent artifact class was lithic debitage, followed distantly by bone debitage, bivalve umboes, and lithic tools. The assessment of site significance is explicitly linked to the existing prehistoric research design for Fort Hood and focuses on data needs of the chronology, subsistence, and technology research domains, supplemented as necessary with information on integrity of deposits. (MM)